U1917 – Module Communication Failure

The ODBII code U1917 indicates a “Module Communication Failure,” meaning there is a problem with communication between the vehicle’s control modules, often due to a fault in the wiring, connectors, or the modules themselves.

The severity of ODBII code U1917 is moderate.

Common Causes For: U1916 U1916: “Module Communication Failure”

• Faulty wiring or connectors
• Failed or malfunctioning control module
• Poor ground connections
• Corrupted software or firmware in the module
• Interference from aftermarket devices
• Low battery voltage or weak battery
• Communication network issues (e.g., CAN bus problems)
• Damaged or corroded pins in connectors
• Faulty or damaged sensors related to the module
• Incompatible or missing modules in the network

Common misdiagnosis for U1917 U1917: “Module Communication Failure”

• Faulty wiring or connectors
• Defective control module
• Software issues or updates needed
• Power supply problems
• Grounding issues
• Intermittent communication issues
• Other communication protocol failures

Common Troubleshooting Steps

The OBD-II code U1917 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between the vehicle’s control modules. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check for Other Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected module(s). Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring harnesses that connect the modules, as these can be prone to wear and tear.
• Check Power and Ground:
• Ensure that the affected module has a proper power supply and ground connection. Use a multimeter to check for voltage at the module’s connector.
• If the module is not receiving power, trace the wiring back to the fuse box and check for blown fuses or damaged wires.
• Test the Module:
• If possible, test the affected module by swapping it with a known good module (if available) to see if the problem persists.
• Some modules may have built-in self-diagnostic capabilities that can provide additional information.
• Check for Communication:
• Use a scan tool to check if the affected module is communicating with other modules. If it is not, there may be a fault within the module itself or the communication network.
• You can also use a scope or a scan tool to monitor the data bus for activity.
• Inspect the CAN Bus:
• If your vehicle uses a Controller Area Network (CAN) bus, check for issues with the bus itself. Look for short circuits, open circuits, or interference that could disrupt communication.
• Use a CAN bus tester if available to check for proper signal levels and integrity.
• Check for Software Updates:
• Sometimes, communication issues can be resolved with a software update. Check with the vehicle manufacturer for any available updates for the affected module(s).
• Clear Codes and Test Drive:
• After performing any repairs or adjustments, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Consult Technical Service Bulletins (TSBs):
• Check for any TSBs related to the specific make and model of your vehicle. Manufacturers may have issued guidance on common communication issues.
• Seek Professional Help:
• If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with your vehicle’s specific systems. By following these troubleshooting steps, you can systematically identify and resolve the underlying cause of the U1917 code.